She attended the Welbeck Defence Sixth Form College on an Army scholarship and planned to join the Royal Engineers as an Engineering Officer. Her army career was ended by arthritis. She studied at the University of Birmingham and graduated in 2011 with a Bachelor of Science degree in physics.
She is the sister of Monica Relph, GB Women's Senior rowing Squad member. The sisters were the first to compete for Great Britain in a World Rowing Championships at Chunju, South Korea in August 2013, when Monica rowed in the GB Women's Quad.
Relph was introduced to the sport of rowing in August 2010 by her older sister, who had rowed internationally for Great Britain. In November 2010 she finished second in the British Indoor Rowing Championships.
In 2011 she competed at the at World Rowing Championships held at Lake Bled, Bled, Slovenia. She won the gold medal in the Legs Trunk and Arms mixed Coxed Four (LTAMix4+) event alongside crewmates Naomi Riches, David Smith, James Roe and Lily van den Broecke, the cox. They completed the one kilometre course in a time of three minutes, 27.10 seconds, finishing nearly five seconds ahead of the second placed Canadian boat. The result meant that Great Britain qualified a boat for the 2012 Summer Paralympics in London. The crew repeated their gold medal result at the Munich World Cup event in 2012.
The GB LTAM4+ crew retained their World Champions crown in August 2013 at Chungju, South Korea. Relph, along with Riches and new crew members Oliver Hester, James Fox and cox Oliver James, took gold in a time of 3min 16.12sec, ahead of Italy (silver) and South Africa (bronze)
She was selected along with Riches, Smith, Roe and van den Broeke, to represent Great Britain at the 2012 Summer Paralympics in the mixed coxed four event. The event took place from 31 August to 2 September at Eton Dorney, where team GB won the gold medal.
- "Pam Relph". British Paralympic Association. Retrieved 25 August 2012.
- "Oarsome Pamela makes Team GB squad for 2012 Paralympics". The Bucks Herald. 5 July 2012. Retrieved 25 August 2012.
- "Students row their way into the London 2012 Paralympic Games". London Higher. 28 June 2012. Retrieved 25 August 2012.
- "World Rowing: GB mixed coxed four win adaptive gold". BBC Sport. 4 September 2011. Retrieved 25 August 2012.
- "Wham, bam thank you Pam as rower gets gold to set up London 2012 dream". The Bucks Herald. 8 September 2011. Retrieved 25 August 2012.
- "2012 Paralympics: GB rowing's mixed coxed four - who's who?". BBC Sport. 25 August 2012. Retrieved 25 August 2012.
- "Mixed Coxed Four - LTAMix4+". The London Organising Committee of the Olympic Games and Paralympic Games Limited. Retrieved 25 August 2012.
- The London Gazette: . 29 December 2012.
-  Cabinet Office